Loop-taker for sewing-machines.



LS. PINCE. LOOP TAKER PQR SEWING MAO'HNES APPLIGAMOH NLRB MM. m2.

Patented Des. 31, W12.

UNITED STATES PATENT OFFICE.

JOHN S. FINCH, OF BRIDGEPO/RT, CONNECTICUT, ASSIGNOR T0 THE SINGER MANU-FACTURING COMPANY, A CORPORATIONI OF NEW JERSEY.

LOOP-TAKER FOB. SWING-MACHINES.

Specification of Letters Patent.

Patented Dec. 31, 191 2.

Application tlled Haren 22, 1912. Serial No. 685,591.

T0 all 'whom it may con/cern:

Be it known that I, JOHN S. FINCH, a

citizen of the United States, residing atl Bridgeport, in the county ofFairfield -and State of Connecticut, have invented certain' loop about acop orl obbi'n of under thread held in a non-'rotating bobbin-easemounted lin an annular groove in the inner wall of the flange formingthe cast-ofi' portion of the'loop-taker, substantially as is representedby U.S. .patent to lV. F. Dial, No. 480,181, dated August 2, 1892, andas machines of this type are well understood by those versed in the art,the present description will be confined, in so far as is possible, to,the newffeat-ures in construction.

In the early constructions of loop-takers of the'character referred toabove, the extension leading from the loop-taker throat tp the cast-offis convexed, between the base of the loop-seizing point and theperiphery of the flange, in the direction of its rotation; and as iswell understood, when the loopseizing point has entered the thread loopa sufficient distance to place the latter in contact with the loop-takerthroat, the further rotation of the loop-taker draws from the supply,through the needle eye, suflicient thread to permit the bobbin-ease topass through the loop, the thread being drawn over the convex portion,which offers a substantial resistance to the enlargementJ of the loopand the casting of the latter about the bobbin-case. When employing aSlack twisted thread, as is common to mercerized sewing cottons; suchresistance demands a substantial decrease in the speed of the machinefrom what would be practical in connection with the use of smooth, welltwisted, sewing threadhand even when the thread is of the most favorabletwist and finish, such frictional engagement is detrimental to qlilalityand quantity of product, if the mac ine is operated at a comparativelyhigh s eed.

pTo facilitate the relative action of'looptaker and needle thread is theobject of the present invention, and to this end the throat extension isso shaped as to permitl the thread to lie in a straight line, thuseliminating the binding or frictional condition incident to its drawingover the convex surface of said extension.

In the accompanying drawings illustrating the invention, in the severalfigures ot` which like' parts are similarly designated, Figure 1 is aview, in elevation, of a looptaker equipped with the present invention;Fig. 2 is a view in section on the line A-B, Fig. 1; Fig. 3 is an edgeview of the looptaker shown in Fig. 1 and Fig. 4 isa plan 'view of thebase portion of one form of commercial bobbin-case adapted for use inconnection with the present loop-taker.

Referring to the figures, the loop taker con'lprises the base or backwall 1 l'ivmg formed integral with it a flange 2 temnating at one end ina loop-seizing point 3 and at its opposite end in a heel 4, said flangebeing partially cut away for a portion of its length to accommodate themounting of thc adjustable gib 5. At the base of the flange 2 is .formeda guideway 6 for the reception of the guide flange 7 of the bobbincasebase 8, the adjustable gib 5 making it: convenient to remove Aor replacethe base 8, if desired` said gib being secured in operative relationshipwith said base by suitable screws (not. shown) passing through open;ings, as 9, formed in said flange, and threaded into openings, as 10,formed in said 11 represents a bracket or lug extending out from thebobbin-case base 8 and which` in practice contacts with a stationary lug(not shown) to hold said base against accidental rotation, and 12 is abobbin-case base stud on which is mounted the commonly employedbobbin-case cap (not shown), betweenv which and said base is mounted torotate the .commonly employed under thread bobbin or cop (not shown).

13 represents the loop-taker throat, 14 the throat extension, 15 theneedle thread cast-oil and 16 an inclined edge formed by -theintersection of said extension and castolf, the inner edge of saidinclined edge and the lower edge 0f said extension intersectin andterminating at the inner edge of sai cast-off.

17 represents a thread-loop guard formed integral with the loop-takerflange and acting to prevent the inner half of the thread 5 not limitedin this respect, as it is practical to substitute the commonly employedl0optaker Washer, such, for instance, asis shown at the back of theloop-taker in full-line Figs. 7 and 8 and in central cross-section,

Figs. 5 and E), of Patent No. 480,181 referred to above.

In the operation of the loop-taker, as the needle thread passes in thedirection of Y its length-about the throat, the rotation of theloop-taker causes the thread to ride the incline 16 its entire length(see Fig. 1), the throat acting as a pivot for the t-hread, and theincline acting to hold that portion of the thread leadingfrorn saidthroat to 20`said incline in a straight line, as will be readilyunderstood.

The throat extension 14 and integrally vformed loop guard 17 constitutethe constructive -features important to the present invention, but assuch features do not materially change the mode of operation for formingthe Stitch illustrated and described in the above :mentioned patent,further reference to such operation is deemed un- 0 necessary.`

Claims l. Ina loop-taker for sewing machines for engaging a loop ofneedle thread and without passing therethrough castingdt about the'underthread, the combination of a loop-seizing point, a needle thread cast-'ol", ay throat,.a throat extension, and an inclined edge formed at theintersection of said cast-off and throat extension, Said inclinededge'acting to-hold in a. straight line that vportion of the needlethread loop leading from said inclined edge to said throat as 'said loopis carried by the rotation ,of the loop-taker in the direction of theaxis of the latter.

2. In a loop-taker for sewing machines for engaging a loop of needlethread and without passing therethrough casting it about the underthread, the combination of a loop-seizing point, a rthread loop guard, aneedle thread cast-off, a throat, a throat extension,. and an'inclinededge formed atI the intersection of said cast-ofi' and throat extension,said inclined edge acting to hold in a straight line that portion of theneedle thread loop leading from said inclined-edge to said throat assaid loop is Acarried by the rotation of the loop-taker in the directionof the axis of the latter.

In testimony whereof, I have signed my name to this specification, inthe presence of two subscribing Witnesses.

JOHN S. FINCH. Witnesses:

T. W. 0mm, ABBIE M. DONIHEE.

